Dear piano techs,
I've been fortunate enough to inherit a harpsichord (Rainer Schütze, Heidelberg / Germany, mid-1970s, historic replica in the Flamish Ruckers family style, two 8' stops, one of them mutable as a lute).
When the instrument was still with my parents (since new), I often tuned it and did minor repairs, e.g. adjusted or replaced quills, adjusted dampers, etc.
I would now like to do a basic regulation. After 45 years of use, key dip / height are still reasonably consistent, but let-off is all over the show, partly because the cloth strips on the back of the keys, on which the jacks rest, have been compacted, and the jack pilot screws vary considerably in their position. I've already removed the keyboard from the cavity for cleaning and inspection.
1) Key-leveling and key-dip:
The keyboard has a simple felt strip on the front rail and back rail, and the only means for adjustment of key height and key dip are balance rail punchings (which I have available, from my piano work). The weight of the jacks keeps the keys down on the back rail, but I would use a small weight while the keyboard is out of the instrument.
The point in the keystroke at which the plectrum plucks the string, is adjusted by a pilot screw at the bottom end of the jack, i.e. turning out the screw raises the jack and results in earlier let-off and correspondingly more aftertouch.
Intuitively, from a player's perspective, I would say the let-off needs to be somewhere close to mid-point.
... Too early, and the finger cannot gain momentum, making for uneven touch.
... Too late, and there is too little aftertouch, making one press into the front rail, and the note sounds too late.
I'm also aware that the low bass strings have more "give" before the plectrum starts to bend, i.e. those keys definitely need sufficient key dip.
Do any of you have any standard reference values for typical harpsichord regulation? I'd be most obliged.
Last edited by Mark R.; 04/20/21 06:49 AM. Reason: correction